The dawn of the iron industry in the territory of Lecco goes back to Roman times when, as clear evidence shows, there was a particularly flourishing mining activity.

A number of different elements led to the early development of this mining activity, that can be briefly summed up in the following key points:

- the location in the Sassina and Varrone valleys of ore-bearing veins;
- vast woodlands capable of supplying the smelting furnaces with fossil carbon;
- abundance of waterways to provide the energy necessary to power the machines;
- the vicinity of a trading point: Milan.

Under the domination of the Visconti and Sforza families the mining activity in Valsassina experienced great growth. After losing the territories of Brescia and Bergamo in the wars against Venice, the nobility of Milan concentrated on the Valsassina mining output for the necessary supplies to the producers of weaponry.
At the same time, the first industries devoted to metal processing began to appear right there in the Lecco zone.

Between the 15th and 16th centuries, the genius of Leonardo Da Vinci also contributed to provide ideas for this process of development, by designing innovative machines with hydraulic drive and carrying out a series of studies to develop the dynamic potential of the territory by making use of new methods of transportation. The ferryboat on the Adda river at Imbersago, still in use today, is the most concrete evidence.